[kernel-hardening] [PATCH v4 2/3] doc: update kptr_restrict documentation

Tobin C. Harding
2017-12-19T21:17:16Z

Recently the behaviour of printk specifier %pK was changed. The
documentation does not currently mirror this.

Update documentation for sysctl kptr_restrict.

Signed-off-by: Tobin C. Harding <me@tobin.cc>
---
Documentation/sysctl/kernel.txt | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt
index 63663039acb7..412314eebda6 100644
--- a/Documentation/sysctl/kernel.txt
+++ b/Documentation/sysctl/kernel.txt
@@ -391,7 +391,8 @@ kptr_restrict:
This toggle indicates whether restrictions are placed on
exposing kernel addresses via /proc and other interfaces.

-When kptr_restrict is set to (0), the default, there are no restrictions.
+When kptr_restrict is set to 0 (the default) the address is hashed before
+printing. (This is the equivalent to %p.)

When kptr_restrict is set to (1), kernel pointers printed using the %pK
format specifier will be replaced with 0's unless the user has CAP_SYSLOG
--
2.7.4